Shelters are full of adult animals. This is a huge plus if you want to skip the demanding "puppy phase." Many adult shelter pets are already house-trained and have established temperaments.
Regardless of where your new best friend comes from, the most important factor is your commitment to their lifelong care.
You have specific needs (like a working dog or a low-shedding pet) and want the highest level of predictability regarding health and behavior.
You are flexible about breed, want to save money, and feel a deep calling to help an animal in need.